Ron's family plans to add a new room to their house. They initially planned the width and the length of the room to be 10 feet and 25 feet. Now they want to add to the width. The amount they want to add to the width is shown by the variable x.

The room is a rectangle
Area of a rectangle = length x breadth
length = 25
breadth = 10+x
Area = 25(10+x)
Area = 250 + 25x square unit
Based on his affirmation that the area of the room = 250 + 25x and he is right
The answer is option D